Nothing is more frustrating then when you plan out your entire grocery store trip, with coupon and deal match ups and shop carefully -only getting the things on the list- and then getting to the check out and seeing that you spent more than you expected. I don't like to make too much of a fuss, and usually I'm in shell shock so it's not until I get to the car or even home that I realize that either my coupons didn't get taken off, or I didn't get credit for one of my purchases -Like buy 10 items get $5.00 off.
If you are a frugal shopper and you feel it's worth your time- here are a few things you can do if/when this happens to you.
If you haven't made it home, take your receipt back inside and go to customer service or ask to speak to the store manager. It always helps if you greet them with a smile. It has been my experience that nobody really wants to go out of their way for someone angry.
If you did make it home, give the store a call- all stores have their number listed on the receipt.
Explain what happened and tell them you won't be able to make it back up today (if you can't) but ask them for a store credit or refund when you come back in.
If you are using Short-cuts or other e-coupon loadable sites and you notice your e-coupon didn't come off at the time of the sale, e-mail or give the company a call. They will almost always give you credit on your card to be used for future purchases.
The important thing to remember is that they are a business that wants your business. If you talk pleasantly and you are understanding that "these things happen" most of the time they will go out of the way to keep you happy and coming back.